A sparring injury has forced Pat Curran (17-4 MMA, 7-1 BFC) to withdraw from his first scheduled title defense against Patricio "Pitbull" Freire (17-1 MMA, 5-1 BFC) at Bellator 73.

A Bellator official on Tuesday told MMAjunkie.com (www.mmajunkie.com) that it hasn't been decided whether Freire will remain on the card, and at this time, a search for a replacement is underway. ESPN.com first reported the injury withdrawal.

Bellator 73 takes place Aug. 24 at Harrah's Tunica Hotel and Casino in Mississippi. The night's main card airs on MTV2 (and in high-definition on EPIX) following prelims on Spike.com.

Curran's cousin and trainer, Jeff Curran, said the Bellator champ was suffering from a knee problem and had decided to focus on boxing rather than muay Thai in the final week of training camp. During a sparring session at his training home near Chicago with a boxer he'd worked with for the past eight weeks, he "ducked into a punch" and suffered a broken orbital.

Jeff Curran estimated it would be approximately three months before his cousin is ready to fight. He said the knee problem did not require surgery and was the result of the typical "wear and tear" during a fight camp.